Designing an Observing System to Study the Surface Biology and Geology (SBG) of the Earth in the 2020s

Abstract

Observations of planet Earth from space are a critical resource for science and society. Satellite measurements represent very large investments and United States (US) agencies organize their effort to maximize the return on that investment. The US National Research Council conducts a survey of Earth science and applications to prioritize observations for the coming decade. The most recent survey prioritized a visible to shortwave infrared imaging spectrometer and a multispectral thermal infrared imager to meet a range of needs for studying Surface Biology and Geology (SBG). SBG will be the premier integrated observatory for observing the emerging impacts of climate change by characterizing the diversity of plant life and resolving chemical and physiological signatures. It will address wildfire risk, behavior, and recovery as well as responses to hazards such as oil spills, toxic minerals in minelands, harmful algal blooms, landslides, and other geological hazards. The SBG team analyzed needed instrument characteristics (spatial, temporal, and spectral resolutions, measurement uncertainty) and assessed the cost, mass, power, volume, and risk of different architectures. We present an overview of the Research and Applications trade‐study analysis of algorithms, calibration and validation needs, and societal applications with specifics of substudies detailed in other articles in this special collection. We provide a value framework to converge from hundreds down to three candidate architectures recommended for development. The analysis identified valuable opportunities for international collaboration to increase the revisit frequency, adding value for all partners, leading to a clear measurement strategy for an observing system architecture.

Error and Uncertainty Degrade Topographic Corrections of Remotely Sensed Data

“…Therefore, they can distort the estimated reflectance spectrum in visible wavelengths, harming snow or vegetation studies that rely on features in this spectral range. Solar illumination geometry in mountains affects current satellite imagery from Landsat 8/9 and Sentinel-2A/B, it affects data from imaging spectrometers EnMAP (Chabrillat et al, 2020) and EMIT (Connelly et al, 2021), and it will affect data from future missions SBG (Cawse-Nicholson et al, 2021;Stavros et al, 2022) and CHIME (Rast et al, 2021). Locally, fine-resolution DEMs will be available from lidar, InSAR, or structure-from-motion deployed from drones or aircraft, and slightly coarser DEMs will be available using structure-from-motion from spaceborne data.…”

Error and Uncertainty Degrade Topographic Corrections of Remotely Sensed Data

“…Solar illumination geometry in mountains affects current satellite imagery from Landsat 8/9 and Sentinel-2A/B, it affects data from imaging spectrometers EnMAP (Chabrillat et al, 2020) and EMIT (Connelly et al, 2021), and it will affect data from future missions SBG (Cawse-Nicholson et al, 2021;Stavros et al, 2022) and CHIME (Rast et al, 2021). Locally, fine-resolution DEMs will be available from lidar, InSAR, or structure-frommotion deployed from drones or aircraft, and slightly coarser DEMs will be available using structure-from-motion from spaceborne data.…”

Simulating Global Dynamic Surface Reflectances for Imaging Spectroscopy Spaceborne Missions: LPJ‐PROSAIL

“…Over the next decade, an emergence in Earth observations using imaging spectroscopy will take place; in early 2022, DLR launched the Environmental Mapping and Analysis Program (ENMAP), and in the summer of 2022, NASA launched Earth Surface Mineral Dust Source Investigation (EMIT, Connelly et al., 2021). By the end of this decade, NASA will have launched the Surface Biology and Geology (SBG) mission (Schimel & Poulter, 2022; Stavros et al., 2022), and ESA will have launched the Copernicus Hyperspectral Imaging Mission for the Environment (CHIME) mission (Nieke & Rast, 2018), providing global VSWIR retrievals at 10‐nm spectral resolution, with high signal‐to‐noise, 30‐m spatial resolution, and with potentially less than 8‐days revisit when the SBG and CHIME constellation are taken together.…”